大约有 47,000 项符合查询结果（耗时：0.0503秒） [XML]
Difference between Pragma and Cache-Control headers?
...
Pragma is the HTTP/1.0 implementation and cache-control is the HTTP/1.1 implementation of the same concept. They both are meant to prevent the client from caching the response. Older clients may not support HTTP/1.1 which is why that header is still in use.
...
Count(*) vs Count(1) - SQL Server
Just wondering if any of you people use Count(1) over Count(*) and if there is a noticeable difference in performance or if this is just a legacy habit that has been brought forward from days gone past?
...
Remove duplicate values from JS array [duplicate]
...
Quick and dirty using jQuery:
var names = ["Mike","Matt","Nancy","Adam","Jenny","Nancy","Carl"];
var uniqueNames = [];
$.each(names, function(i, el){
if($.inArray(el, uniqueNames) === -1) uniqueNames.push(el);
});
...
Simulator error FBSSystemServiceDomain code 4
...
Go to the iOS Simulator menu and select Reset Content and Settings.
Alternatively, you could quit and reopen the Simulator.
share
|
improve this answ...
Difference between dispatch_async and dispatch_sync on serial queue?
...k is finished whereas dispatch_async return after it is added to the queue and may not finished.
for this code
dispatch_async(_serialQueue, ^{ printf("1"); });
printf("2");
dispatch_async(_serialQueue, ^{ printf("3"); });
printf("4");
It may print 2413 or 2143 or 1234 but 1 always before 3
for ...
Switch statement: must default be the last case?
...
The C99 standard is not explicit about this, but taking all facts together, it is perfectly valid.
A case and default label are equivalent to a goto label. See 6.8.1 Labeled statements. Especially interesting is 6.8.1.4, which enables...
Android studio, gradle and NDK
I am very new to this whole gradle and Android Studio support. I have managed to convert my android project to gradle using the export option.
...
How to concatenate twice with the C preprocessor and expand a macro as in “arg ## _ ## MACRO”?
...
Standard C Preprocessor
$ cat xx.c
#define VARIABLE 3
#define PASTER(x,y) x ## _ ## y
#define EVALUATOR(x,y) PASTER(x,y)
#define NAME(fun) EVALUATOR(fun, VARIABLE)
extern void NAME(mine)(char *x);
$ gcc -E xx.c
# 1 "xx.c"
# ...
What is the difference between '@' and '=' in directive scope in AngularJS?
I've read the AngularJS documentation on the topic carefully, and then fiddled around with a directive. Here's the fiddle .
...
How to get line count of a large file cheaply in Python?
I need to get a line count of a large file (hundreds of thousands of lines) in python. What is the most efficient way both memory- and time-wise?
...